RP01 and RP02 Disk Drives - DEC

This is a discussion on RP01 and RP02 Disk Drives - DEC ; pechter@pechter.dyndns.org (William Pechter) writes:
> The RP07 was a late 80's Sperry product in the 450+ mb range used to
> fill the gap before the RA81 came out in numbers.
The RP07 was an *early* 80s (or even late ...

Re: RP01 and RP02 Disk Drives

pechter@pechter.dyndns.org (William Pechter) writes:
> The RP07 was a late 80's Sperry product in the 450+ mb range used to
> fill the gap before the RA81 came out in numbers.

The RP07 was an *early* 80s (or even late 70s) Sperry product in the 450-500MB
range used to increase the available disk space/square foot of computer room.
We had them at Chicago by 1981, and there was an RP07 login structure on each
LOTS system in 1984.

Re: RP01 and RP02 Disk Drives

"Tom94022" writes:
> RP07 ISS equivalent to IBM3350?? or maybe just a 50% increase over RP06
> (300 MB)
> [MB capacities are in million bytes in the IBM full track record format]

In that format, the RP07 would come out to about 500MB. I don't think it was
a 3350 equivalent--was the 3350 track size 19069 bytes? (3330-II was 13030,
right?)
> FWIW, the one salesperson who sold most these products to DEC was
> Arnold Cooley, working variously for Memorex and ISS. Also there are
> two operational RP06's at the PDP-10 project - probably the oldest
> operating disk drives in the world.

There are three operational RP06s at PDPplanet, of which two have been spinning
for the last 18 months or longer. How long have yours been up? What are they
attached to? How are they being used?

Re: RP01 and RP02 Disk Drives

On Fri, 19 Jan 2007, Rich Alderson wrote:
> The RP07 was an *early* 80s (or even late 70s) Sperry product in the 450-500MB
> range used to increase the available disk space/square foot of computer room.
> We had them at Chicago by 1981, and there was an RP07 login structure on each
> LOTS system in 1984.

I created the first 4-RP07 PS on the new Score in 1983, much to the
chagrin of Digital field service who complained that nobody could ever
need a 2GB filesystem and that it couldn't be backed up.

Actually, the real problem was that the early RP07 HDAs were very
unreliable and generally would fail after a month or two of use. Digital
knew this, but sold them anyway.

Restoring a 2GB filesystem from 9-track tape required much more time than
restoring a 512MB filesystem, and the fact that it was PS: meant that this
restore time was downtime rather than a mere mountable structure.

Fortunately, my boss backed me up, and make it clear that Digital that we
expected reliable hardware and not workarounds for unreliable hardware.
IIRC, they eventually ended up replacing all the HDAs with a second
generation that didn't fail.

One thing that people forget about the old DEC mainframe hardware is how
unreliable it was. I put in a great deal of effort in TOPS-20 to banish
software crashes (and largely succeeded with the exception of the TCP/IP
code), but hardware was a different issue. Each KL had its own
idiosyncracies. The old Score regularly crashed with microcode CRAM
parity errors before it was finally tracked down to a clock cable on the
backplane (said cable being cut and pasted to the door of the processor as
a trophy). That was nothing compared to the crashes suffered by the
Stanford business school machine in 1979 (and memorialized in a T-shirt
reading "I survived the crash of 1979"). KS systems were generally
better, although people came to dread the failure of the Mighty Mite power
supply.

It wasn't just customers. DEC's TOPS-20 developers were saddled with
systems (such as 2102) which were infamously unreliable.

Later production KLs were quite a bit more reliable, but by then it was
too late.

Re: RP01 and RP02 Disk Drives

Rich Alderson wrote:
> [...snip...]
> In that format, the RP07 would come out to about 500MB. I don't think it was
> a 3350 equivalent--was the 3350 track size 19069 bytes? (3330-II was 13030,
> right?)

Good grief :-) I thought I was the only pervert on the planet
to have these figures (13,030 and 19,069) permanently implanted
in my brain.

Re: RP01 and RP02 Disk Drives

In article ,
Rich Alderson wrote:
>pechter@pechter.dyndns.org (William Pechter) writes:
>
>> The RP07 was a late 80's Sperry product in the 450+ mb range used to
>> fill the gap before the RA81 came out in numbers.
>
>The RP07 was an *early* 80s (or even late 70s)

TW's RP07 work was after 7.01, IIRC. Check the date on his
listings.
> Sperry product in the 450-500MB
>range used to increase the available disk space/square foot of computer room.
>We had them at Chicago by 1981, and there was an RP07 login structure on each
>LOTS system in 1984.

They were not mountable and couldn't be used as the boot device. In
our shop it was pretty useless except for scratch storage.

/BAH

Re: RP01 and RP02 Disk Drives

510MB or 512MB.
> [MB capacities are in million bytes in the IBM full track record
> format]
> FWIW, the one salesperson who sold most these products to DEC was
> Arnold Cooley, working variously for Memorex and ISS. Also there
> are two operational RP06's at the PDP-10 project - probably the
> oldest operating disk drives in the world.
> But, has ANYONE SEEN AN RP01 or RP02 recently?

No, but I have 2 RP06s, a 667 and 4 RP07s...

Re: RP01 and RP02 Disk Drives

Mark Crispin writes:
> Actually, the real problem was that the early RP07 HDAs were very
> unreliable and generally would fail after a month or two of use.
> Digital knew this, but sold them anyway.

They also had a glass fibre based absolute filter, and with age it
would get fragile. Any extra vibration was likley to send a cloud and
happy to meet you glass fibres into the HDA... ISS did an ECO with a
Goretex filter for that one.

That usually happened on the -10 side, too. But it was
software and not hardware that were "first time" products.
It had to be software and usually not at the monitor level.

CSS had been disbanded on the PDP-10 side and all those projects
were handled by the regular guys.

/BAH

Re: RP01 and RP02 Disk Drives

In article <8764b17q7x.fsf@k9.prep.synonet.com>, wrote:
>Mark Crispin writes:
>
>> Actually, the real problem was that the early RP07 HDAs were very
>> unreliable and generally would fail after a month or two of use.
>> Digital knew this, but sold them anyway.
>

I'm not so sure we knew it in advance. The RP07 seemed to be a lot
worse engineered than the standards we had.

The head retract on power loss was abysmal and battery packs were added
and IIRC they were adjusted with levels to keep a slight tilt back so
the heads wouldn't slip back out onto the "semi-sealed" disk HDA.

The RA81's looked a hell of a lot better until the breather filter glue
disaster made them look like a pile of dreck.

>They also had a glass fibre based absolute filter, and with age it
>would get fragile. Any extra vibration was likley to send a cloud and
>happy to meet you glass fibres into the HDA... ISS did an ECO with a
>Goretex filter for that one.

Did that ECO ever get to DEC?

I only worked on one RP07 in my field service days... the one at E.R.
Squibb in East Brunswick, NJ had HDA failure and it took Regional or
District Support to come down to approve the HDA replacement.

I remember scoping the drive and sleeping on my down coat behind the
11/780 while waiting for the support guys to show up to authorize the
swap. The branch support guy was already out there with me...

They were trying really hard to get the reliability up and hold the
DEC Sperry engineers to the fire to get these fixed and reliable.

I think they flew an HDA in to Newark for this one.

I realized this service call was around '84 or 85 -- so I guess my
date estimate for the RP07 was really off a few.

Bill
--
--
"When I think back on all the crap I learned in Vax school
It's a wonder I fixed anything at all." (to the tune of Kodachrome)
pechter-at-ureach.com

Re: RP01 and RP02 Disk Drives

On Sat, 20 Jan 2007, jmfbahciv@aol.com wrote:
> >The RP07 was an *early* 80s (or even late 70s)
> TW's RP07 work was after 7.01, IIRC. Check the date on his
> listings.

The new Score's RP07s were in January 1983, so RP07s were available by
then. I doubt that they were available in the 1970s.

-- Mark --

http://panda.com/mrc
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.

Re: RP01 and RP02 Disk Drives

On Sat, 20 Jan 2007, William Pechter wrote:
> >> Actually, the real problem was that the early RP07 HDAs were very
> >> unreliable and generally would fail after a month or two of use.
> >> Digital knew this, but sold them anyway.
> I'm not so sure we knew it in advance.

My understanding was that the problems with the RP07 were well known by
the engineers in Marlboro. Perhaps the problem was that management and
marketing wasn't listening -- wouldn't have been the first time.
> I only worked on one RP07 in my field service days... the one at E.R.
> Squibb in East Brunswick, NJ had HDA failure and it took Regional or
> District Support to come down to approve the HDA replacement.

That was a sore spot with customers too. We have a situation where an
RP07 was clearly non-functional, it was on service contract, it hadn't
been abused, and yet we still had to wait for the paper-pushers to approve
the HDA replacement.

This was, mind you, the same year that Digital cancelled 36-bits (although
that didn't happen until May). So customers were not particularly
inclined to be patient when 512MB of their storage was down (or, in the
case of Score, 2GB).

-- Mark --

http://panda.com/mrc
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.

Re: RP01 and RP02 Disk Drives

In article ,
Mark Crispin wrote:
>On Sat, 20 Jan 2007, jmfbahciv@aol.com wrote:
>> >The RP07 was an *early* 80s (or even late 70s)
>> TW's RP07 work was after 7.01, IIRC. Check the date on his
>> listings.
>
>The new Score's RP07s were in January 1983, so RP07s were available by
>then. I doubt that they were available in the 1970s.

I know they weren't. TW's RP07 project was after SMP. Look
in the listing for the date.

/BAH
>
>-- Mark --
>
>http://panda.com/mrc
>Democracy is two wolves and a sheep deciding what to eat for lunch.
>Liberty is a well-armed sheep contesting the vote.

Re: RP01 and RP02 Disk Drives

Not sure. The 4 I have are from a KL10E. They all have off-white
filters, and the Goretex ones are a charming baby blue. They
came from a unisucks site from memory.

Re: RP01 and RP02 Disk Drives

The other fun feature on the RP07s was the $10,000/in wire.

One jumper removed, $7000. They did also run the formatter for
you, and MAY have restored your data. For a 780, you needed to
add a second memory controller and interleave them to avoid
data overruns on the SBI. 10s and 11/70s had no need of such.

Re: RP01 and RP02 Disk Drives

On Sun, 21 Jan 2007, jmfbahciv@aol.com wrote:
> >The new Score's RP07s were in January 1983, so RP07s were available by
> >then. I doubt that they were available in the 1970s.
> I know they weren't. TW's RP07 project was after SMP. Look
> in the listing for the date.

With all due respect, Barb; Score was a TOPS-20 system. So TW's RP07
project for TOPS-10 is somewhat orthogonal.

However, I am sure that you are right: RP07s were not available in the
1970s.

I'm a bit surprised that TW had to have a product to do RP07s in TOPS-20.
The RP07 was programmed more or less the same as the RP04 and RP06. Once
you had the RP04/6 code written, an RP07 was simply a device with
different geometry. The RP20 was a different matter altogether (did
TOPS-10 ever support the RP20, a.k.a. DEC's answer to the SA10?).

Now, implementing RH20 would definitely be a project! From "Tony in RH20
Land" we can see how difficult the RH20 was for someone who works on
software that expects the DF10 ways of doing things. Seemingly, the RH20
was not designed with TOPS-10 considerations in mind.

On the other hand, they did choose the TOPS-10 style 128 word record size.
This was an annoyance to TOPS-20 people who used 512 word pages; the disk
address was based upon a record number in the structure which limited the
maximum number of records in a structure. As distributed by DEC, the
TOPS-20 disk address space could only support a single RP07 in a single
structure. You can actually support as many as 16 RP07s (8GB) in a
structure if you go to whole page record sizes (gain of 2 bits) and adjust
the disk address bits (gain of two more bits).

The Panda monitor does something more modest; it adjusts the disk address
bits in a way that gains one bit (thus allowing a two-RP07 structure) but
can still mount DEC filesystems. The code to get the other three bits
would make it impossible to mount a DEC filesystem.

Re: RP01 and RP02 Disk Drives

In article ,
Mark Crispin wrote:
>On Sun, 21 Jan 2007, jmfbahciv@aol.com wrote:
>> >The new Score's RP07s were in January 1983, so RP07s were available by
>> >then. I doubt that they were available in the 1970s.
>> I know they weren't. TW's RP07 project was after SMP. Look
>> in the listing for the date.
>
>With all due respect, Barb; Score was a TOPS-20 system. So TW's RP07
>project for TOPS-10 is somewhat orthogonal.

Now listen, you young whippersnapper. When a new piece of gear
showed up, TW was the first one to make it work. And THEN the
-20 people wrote the code a second time.

That's how things happened.

/BAH

Re: RP01 and RP02 Disk Drives

On Mon, 22 Jan 2007, jmfbahciv@aol.com wrote:
> >> >The new Score's RP07s were in January 1983, so RP07s were available by
> >> >then. I doubt that they were available in the 1970s.
> >> I know they weren't. TW's RP07 project was after SMP. Look
> >> in the listing for the date.
> >With all due respect, Barb; Score was a TOPS-20 system. So TW's RP07
> >project for TOPS-10 is somewhat orthogonal.
> Now listen, you young whippersnapper. When a new piece of gear
> showed up, TW was the first one to make it work. And THEN the
> -20 people wrote the code a second time.
> That's how things happened.

Fortunately, TOPS-20 kept edit histories.

RP07 support was added to TOPS-20 on May 6, 1978.

TOPS-10 sources do not have edit histories prior to 1980, and what exists
is just a reference to an MCO number.

If you still contend that TW added RP07 support to TOPS-10 before it was
added to TOPS-20, then you must withdraw your claim that TW did it in the
1980s and show evidence that TW did the work prior to May 6, 1978.

Human memories, while valuable in other contexts, do not constitute proof.

-- Mark --

http://panda.com/mrc
Democracy is two wolves and a sheep deciding what to eat for lunch.
Liberty is a well-armed sheep contesting the vote.

Re: RP01 and RP02 Disk Drives

R.A.Omond wrote:
> Rich Alderson wrote:
> > [...snip...]
> > In that format, the RP07 would come out to about 500MB. I don't think it was
> > a 3350 equivalent--was the 3350 track size 19069 bytes? (3330-II was 13030,
> > right?)
>
> Good grief :-) I thought I was the only pervert on the planet
> to have these figures (13,030 and 19,069) permanently implanted
> in my brain.
Actually isn't the magic number for the 3330 13,440, that is, the
number of servo (or data) bytes index to index. 13,030 is the length
of a full track record 1 with no key field in IBM format. The 3330-11
was the same. DEC used a sector architecture which was more efficient
than IBM at that sector size, something like 2 additional sectors per
track.

I think the 3340 magic number was 20,160. I don't recall any later
ones but all of them had a fixed number of servo bytes index to index
to which the data was phase locked, usually at a multiple of 8.

I'm glad to see there are other preverts around :-)

Re: RP01 and RP02 Disk Drives

Tom94022 wrote:

(snip)
>>Good grief :-) I thought I was the only pervert on the planet
>>to have these figures (13,030 and 19,069) permanently implanted
>>in my brain.
> Actually isn't the magic number for the 3330 13,440, that is, the
> number of servo (or data) bytes index to index. 13,030 is the length
> of a full track record 1 with no key field in IBM format. The 3330-11
> was the same. DEC used a sector architecture which was more efficient
> than IBM at that sector size, something like 2 additional sectors per
> track.

The number I remember for the 3330 is 13165, then you subtract 135 for
each block, such that a full track block is 13030. Half track would
be (13165/2)-135. Other drives, such as the 3214, were not described
that way, but such that the gap overhead didn't apply to the first
block. The 13440 might include R0, which didn't hold user data.

The next number that was important was 3120, a multiple of 80 that
was reasonably efficient on both 2314 and 3330. (If you didn't
know which drive you were going to write on.)

-- glen

Re: RP01 and RP02 Disk Drives

In article ,
Mark Crispin wrote:
>On Mon, 22 Jan 2007, jmfbahciv@aol.com wrote:
>> >> >The new Score's RP07s were in January 1983, so RP07s were available by
>> >> >then. I doubt that they were available in the 1970s.
>> >> I know they weren't. TW's RP07 project was after SMP. Look
>> >> in the listing for the date.
>> >With all due respect, Barb; Score was a TOPS-20 system. So TW's RP07
>> >project for TOPS-10 is somewhat orthogonal.
>> Now listen, you young whippersnapper. When a new piece of gear
>> showed up, TW was the first one to make it work. And THEN the
>> -20 people wrote the code a second time.
>> That's how things happened.
>
>Fortunately, TOPS-20 kept edit histories.

So did TOPS-10. We didn't put them in the sources.
>
>RP07 support was added to TOPS-20 on May 6, 1978.
>
>TOPS-10 sources do not have edit histories prior to 1980, and what exists
>is just a reference to an MCO number.

Then you can find the MCO in the x.MCO that was shipped on the tape.

Now, if the RP07 was done before 1980, then there must have been
an RP07.LIR. I don't remember that being done.
>
>If you still contend that TW added RP07 support to TOPS-10 before it was
>added to TOPS-20, then you must withdraw your claim that TW did it in the
>1980s and show evidence that TW did the work prior to May 6, 1978.
>
>Human memories, while valuable in other contexts, do not constitute proof.

Yea, and mine is screwed up. I don't remember an RP07 hung on
the -20 machine. So, given your evidence and my knowledge of
how stuff worked, the folowing may be what happened.

The -20 got the RP07 and did their development and testing. Then
the RP07 was moved to the TOPS-10 machine and TW did his
work. I do know that the RP07 stayed on Kl1026.

If, as you say, it was just a rearrangement of the RP06 stuff, having
the -20 do it first would then make sense.

The usual procedures were for TW to do the first implementation of
a piece of new gear. Then the -20's implementation didn't have
to deal with the hardware types, the necessary ECO work was already
done and the -20 developer could use TW's experience for all the
stuff to avoid.